Preparation and characterization of a mesoporous silica-based copolymer loaded with bis(2-ethylhexyl) phosphate for the efficient separation of trace radium from natural thorium

A silica-supported copolymer loaded with bis (2-ethylhexyl) phosphate was prepared and first investigated for the separation of trace radium from natural 232 Th. Results showed that the adsorbent was prepared successfully with ultrahigh selectivity and ultrafast adsorption kinetics towards thorium, making the separation easy and convenient. The chemical recovery rate to radium reached 96.7%, and the decontamination factor to thorium exceeded 10 5 . Generally, this work demonstrated the feasibility of using this material and method to directly separate 228 Ra and 224 Ra from 232 Th, rendering it significant in the future preparation and application of 212 Pb.